What is the chief way in which the bad angels try to harm us?
The chief way in which the bad angels try to harm us is by tempting us to sin.
(a) Devils are sometimes permitted to enter the body of a man and to exercise power over his faculties—a state known as diabolical possession; or the,, are permitted to torment a person from without—a state known as diabolical obsession.
(b) Diabolic possession and obsession are permitted by God to show forth His glory, to punish sin, to bring sinners to repentance, or to give occasion for the exercise of virtue.
(c) When the devil uses the body of a possessed person to say or do evil things, the person is not guilty of sin, provided he does not freely consent.
(d) Exorcism is the act of driving out or warding off evil spirits from persons, places, or things possessed or infested by them. The Church received from Christ the power of exorcism.
(e) An exorcist is one who has power, conferred by a bishop, to exorcise demons. The order of exorcist is the third of the four minor orders of the Western Church. Only with the permission of his bishop is a priest allowed to use his power of exorcising evil spirits.